Monochrome and polychrome printing



Feb. 27, 1934. K. ALBRECHT 0 MONOCHROME AND POLYCHROME PRINTING Filed June 18. 1931 5 Sheets-Sheet 1 Feb. 27, 1934. K ALBRECHT 1,949,001

MONOCHROME AND POLYCHROME PRINTING Filed June 18 1931 I 3 Sheets-Sheet 2 Feb. 27, 1934. K. ALBRECHT MONOOHROME AND POLYCHROME PRINTING Filed June 18. 1931 3 Sheets-Sheet 3 mguT'dR Patented Feb. 27, 1934 UNITED STATES PATENT OFFICE MONOCHROME AND POLYCHROME PRIN TING

Germany Application June 18, 1931, Serial No. 545,290 In Germany June 10, 1930 4 Claims.

This invention relates to apparatus by which the production of monochrome and polychrome printing on the first form or prime and on the second form or backing in a single operation is rendered possible on polychrome rotary machines for sheets. With the apparatus according to the invention, therefore, a sheet can be printed at will either on one side only, in one colour or in a plurality of colours, or else on both sides, the inner form being either in one colour or in polychrome, and the second form also being either in monochrome or in polychrome, in each case in a single operation.

The invention consists essentially in the fact that at the point of transition from the first form to the second form a reversing device for the sheet is proivded, which can be connected to the machine when desired, and can be disconnected for sheets that are only to be printed on one side.

The invention is diagrammatically illustrated by way of example in the accompanying drawings, in which Figure 1 shows a polychrome intaglio rotary machine, which is provided with a device which enables it to be employed when desired for monochrome printing on the prime or on the backing;

Figures 2 and 3 show means for delivering the sheet to the reversing device, and

Figures 4 to 6 show a further constructional form of the delivering means shown in Figs. 2 and 3.

For polychrome printing on one side of the sheet the method of working of the machine is as follows:---

The sheet I; is delivered by the feeding means a to the grippers c of the first printing mechanism and the printed sheet is delivered to the grippers e of the spreader d, which delivers the sheet to a set of moving bands with the printed side of the sheet upwards. The set of bands 1 guides the sheet to the feeding means g of the second printing mechanism,- by which it is printed on the same side in another colour. The arrangement and method of working of the machine up to this point is known.

According to the invention to enable the sheet to be printed on both sides a turning device 11. is provided, which is disconnected when the sheets are only to be printed on one side. When printing both the prime and the backing, the device It, with the grippers i, takes over the printed sheet from the spreader d and places it upon a set of bands 70, or upon the suitably lengthened set of bands 1. By the interposition of the 55 device It the sheet is supplied with the printed side downwards to the feeding means 0, so that when printing next occurs, the previously unprinted side of the sheet is printed. The sheet is therefore printed both onthe first side and on the second. so

The essential point is that the delivery of the sheet by the turning device h to the set of bands It is eifected in such a manner that the printed side, which is facing downwards, does not suffer any injury. In order to attain this result aco cording to the invention special means are provided, which, in the constructional example illustrated in Figures 2 and 3, consist in two blowing arrangements 1 and m. The blower 1 acting from below keeps the sheet I) in suspension yo (Fig. 2) until it has to be delivered to the set of bands 10. At the moment of delivery the blower Z is stopped and the blower m acting from above is turned on, which delivers the sheet b to the sheet delivery is (Fig. 3). The changing over of the blowers is efiected by means of two cam discs 11 and 1', which control in opposite directions valves s and t in the supply pipes leading to the blowing nozzles l and m.

A further possibility for the satisfactory trans- 0 fer of the sheet b from the reversing device h. to the set of bands It is given in the constructional form according to Figures 4 to 6, in which the set of bands 7c, before the sheet delivery, has the direction of running of the'sheet b, but the 5 bands k are reversed at the moment of delivering the sheet, and then supply the sheet b to the next printing mechanism. The reversal is obtained by means of a reversing clutch n, which is controlled by a cam disc 11. (Fig. 6), through the medium of a lever 10 from the reversing device h. The blower m assists in the transfer of the sheet from the turning device it to the set of bands It.

In the accompanying drawings, the apparatus has only been illustrated for monochrome prime {)5 and backing printing. Should polychrome prime and backing printing be required, further printing mechanisms must be arranged before and after the reversing device h according to the number of colours. In each case, however, only one turning device is necessary, namely at the place at which the transition from prime to backing occurs.

What I claim is:--

1. Apparatus for the production of monochrome and polychrome printing on one or both sides of a sheet in one operation, comprising the combination of a plurality of rotary printing mechanisms, sheet feeding means for each of said printing mechanisms, sheet transfer means interposed between the printing mechanisms and arranged to withdraw the sheet from one printing mechanism, conveying means arranged to receive the sheet withdrawn from the said printing mechanism and convey it to the sheet feeding means of the next printing mechanism to receive a second impression on the same side, with sheet reversing means arranged to withdraw the sheet from the sheet transfer means, in the opposite direction to the direction of conveyance of the sheet by the said conveying means and delivering the sheet inverted to the sheet feeding means of the next printing mechanism with the leading edge of the sheet to the rear to enable the next printing mechanism to print the sheet on the reverse side.

2. Apparatus for the production of monochrome and polychrome printing on one or both sides of a sheet in one operation, comprising the combination of a plurality of rotary printing mechanisms, sheet feeding means for each of said printing mechanisms and sheet transfer means interposed between the printing mechanisms and comprising a set of conveyor bands having grippers arranged to seize the leading edge of the sheet, to withdraw the sheet from one printing mechanism, and deliver it to the sheet feeding means of the next printing mechanism to receive a second impression on the same side, with sheet reversing means comprising a set of conveyor bands having grippers arranged to seize the leading edge of the sheet, to withdraw the sheet from the grippers of the sheet transfer means, invert the sheet and deliver it to the sheet feeding means of the next printing mechanism with the leading edge of the sheet to the rear, to enable the next printing mechanism to print the sheet on the reverse side.

3. Apparatus as set forth in claim 2, in which the reversing means comprises a second set of 8 conveyor bands arranged below the conveyor bands of the set which seize the leading edge of the sheet and withdraw the sheet from the sheet transfer means, for delivering the sheet to the sheet feeding means of the next printing mech- .85 anism and a blower located above the second set of conveyor bands and arranged to act on the sheet from above on the sheet arriving in position above the second set of conveyor bands to transfer the sheet to the latter.

4. Apparatus as set forth in claim 2, in which the reversing means comprises a second set of conveyor bands arranged below the conveyor bands of the set which seize the leading edge of the sheet and withdraw the sheet from the sheet transfer means, for delivering the sheet to the sheet feeding means of the next printing mechanism, a blower located above said second set of conveyor bands and arranged to act on the sheet from below to hold the sheet in suspension before transfer of the sheet to the said second set of conveyor hands, a blower located above said second set of conveyor bands and arranged to act on the sheet from above on the sheet arriving in position above the second set of conveyor 10." bands to transfer the sheet to the latter and means for stopping the first blower and starting the second when a sheet is transferred from one set of band conveyors to the other.

KARL ALBRECHT. 

